State of Washington of Ecology Criteria Pollutants and Air ...

DOWRL-96-49 Revision A

UC-630

State of Washington Department of Ecology Criteria Pollutants and Toxic Air Polfutants Phase I Notice of Construction for the Hanford -Site Spent Nuclear Fuel Project--Hot Conditioning System Annex, Project W-484

Date Published

rtment of Energy

7th report has been reproduced from the bcn mailable copy. Avait.bla in P ; ~ P ~ ~ C O P Y andcm'crofrho. Available to the W.S. Dspamnont of Energy and 11s contractors lrom O K r o 01 Sotenof16 and Tschrvcsl Informinon P.O. Box 6 2 Oak Wdge. TN 37831 1615) 576.8401

Available to tho puUs frm tho U 5. Dapamncnl of COIIImtce Nabonal T~shrvcal Informanon Sarvi~o 5285 Pon Royal Road Spnngtnld. VA 22161 (703) 4874650

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DISC&! 5.CHPI8-911

DOE/RL-96-49, Rev. ,E','&& Document ID Number

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CONTENTS

INTRODUCTION ......................... 1.1 PROJECT DESCFUPTION . . . . . . . . . . . . . . . 1.2 FACILITY IDENTIFICATION AND LOCATION

1.2.1 Facility Description . . . . . . . . . . . . 1.2.2 Location of Facility . . . . . . . . . . . . TYPE OF PROPOSED ACTION . . . . . . . . . . . ENVIRONMENTAL CHECKLIST . . . . . . . . . .

1.3 1.4 STATE ENVlROhWENTAL POLICY ACT

. . . . . . . . . . . . . 1

. . . . . . . . . . . . . 4 . . . . . . . . . . . . . 4

. . . . . . . . . . . . . 6

. . . . . . . . . . . . 10 . . . . . . . . . . . . 10

. . . . . . . . . . . . 10

SOURCE INFORMATION ...................... 2.1 PROCESS DESCRIPTION . . . . . . . . . . . . . . . . . . 2.2 SPENT NUCLEAR FUEL RETRIEVAL FROM THE K 2.3 C O L ~ VACUOM DKYI~NG . . . . . . . . . . . . . . . . . 2.4 MULTI-CANISTER OVERPACK STAGING . . . . . . 2.5 HOT CONDITIONING SYSTEM ANNEX . . . . . . . .

2.5.1 ... Process Description and Equipment . . . . . . 2.5.2 2 Process Steps . . . . . . . . . . . . . . . . . . . 2.5.3 .? Solid Warte/Process Exhaust Gases . . . . . .

2.6 INTERIM STORAGE ..................... i

. . . . . .

. . . . . . BASINS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . 11

. . . 11 . . . 14

. . . 15 . . . 17

. . . 18

. . . 18

. . . 22 . . . 24

. . . 24

EMISSION S+JRCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3.1 CRITERIA POLLUTANTS . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3.2 TOXIC AIR POLLUTANTS . . . . . . . . . . . . . . . . . . . . . . . . . 25

REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

R lamllll ... ......

DOEYRL-9&49 Revision A

LIST OF FIGURES

1 . Hanford Site Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2 . OverallSitePlan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

3 . Canister Storage Building and Hot Conditioning System Annex Layout . . . . . . . . . 5

4 . Hot Conditioning System Annex Layout ............................ 7

5 . Hot Conditioning System Annex Central Services Layout . . . . . . . . . . . . . . . . . . 8

6 . Hot Conditioning System Annex Equipment Ventilation . . . . . . . . . . . . . . . . . . 9

7 . Multi-Canister Overpack A&.mbly Waded Closure ...................... 12

8 . Multi-Canister Overpack Mechanical Closure . . . . . . . . . . . . . . . . . . . . . . . . . 13

Element Assembly . . . . . . . . . . . . . . 16 Ventilation Diagram . . . . . . . . . . . . 19

. . . . . . . . . . . . . . . . . . . . . . . . . 21

12 . Hot Conditioning System Equipment rocess Enclosure . . . . . . . . . . . . . . . . . . 23

LIST OF TABLES

1 . Cnteria Pollutants for the Hot Conditioning System Annex . . . . . . . . . . . . . . . . 25

2 . Air Toxic Pollutants from the Hot Conditioning System Annex . . . . . . . . . . . . . . 26

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DOEJRL-96-49 Revision A

CSB CVD

D O W Ecology EXS HCS HCSA HCSE HEPA HWVP MCO NOC PUREX SEPA ShF WAC

. CVDF

LIST OF TERMS

Canister Storage Building Cold vacuum drying Cold Vacuum Drying Facility U.S. Department of Energy, Richland Operations State of Washington Department of Ecology Environmental Impact Statement Hot conditioning system Hot Conditioning System Annex Xot conditioning system equipment High-efficiency particulate ah' Hanford Waste Vitrification Plant Mu_lti-canister overpack Notice of construction Plutonium-Uranium Extraction (Washington) State Environmental Policy Act of 1971 Spent nuclear fuel Washington Administrative Code

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DOURL-96-49 Revision A

CRITERIA POLLUTANTS AND TOXIC AIR POLLUTANTS WASHINGTON STATE DEPARTMEW OF ECOLOGY

PHASE I NOTICE OF CONSTRUCTION FOR THE HANFORD SITE SPENT NUCLEAR FUEL PROJECT- HOT CONDITIONING SYSTEM ANNEX, PROJECT W-484

1.0 INTRODUCTION

This notice of construction (NOC) provides information regarding the source and the air toxic and criteria pollutants resulting from operation of the Hot Conditioning System Annex (HCSA). Additional details on emissions generated by the operation of the HCSA will be discussed again i n the Phas NOC. This Phase I NOC is defined as, constructing the substructure, including but not ted to pouring the concrete for the floor; construction of the process pits and exterior walls; making necessary interface connections to the Canister Storage Building (CSB) ventilation and utility systems for personnel comfort; and extending the multi-canister overpack (MCO) handling machine rails into the HCSA. A Phase I1 NOC, will be submitted for approval prior to installing and is defined as the completion of the HCSA, which will consist of installation of the Hot Conditioning System Equipment (HCSE), air emissions control qbipment, an monitoring equipment.

nt of Energy's spent nuclear fuel (SNF) Site K Basins; Spent nuclear fuel in the

K West Basin is contained in closed canisters, while the SNF in the K East Basin is contained in open canisters, which allow free release of corrosion products to the K East Basin water. Storage in the K Basins was originally intended to be on an as-needed basis to sustain operation of the N Reactor while the Plutonium-Uranium Extraction (PUREX) Plant was refurbished and restarted. The decision in December 1992 to deactivate the PUREX Plant left approximately 2,300 MT (2,530 tons) of N R&;tof SNF in the K Basins with no means for near-term removal and processing.

constructed as an addition to the CSB and will contain the HCSE. m (HCS) will remove chemically-bound water and will passivate

the exposed uranium surfaces asiociated with the SNF. The HCSA will house seven hot conditioning process stations, six operational and one auxiliary pit which could be used as a welding area for final sealing of the vessel containing the SNF, or for neutron interrogation of the vessel containing the SNF to determine residual water content. Figures 1 and 2 contain map locations of the Hanford Site and the HCSA.

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Figure 1. Hanford Site Map.

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Figure 2. Overall Site Plan.

DOEIRL-96-49 Revision A

1.1 PROJECT DESCRIPTION

The SNF presently stored in the K Basins will be retrieved and placed in containers, processed to remove water, and stored dry in accordance with the Huqford Federal Facitiry Agreement 4nd Consenr Order (referred to as the Tri-Party Agreement) (Ecology et al. 1994). Processing of the SNF will take place at the Cold Vacuum Drying Facility (CVDF) and HCSA, while storage of the SNF will take place at the CSB.

The SNF will be removed from the K Basins as part of the SNF retrieval process. The first step in processing will begin at the CVDF, where free water (bulk water [water that surrounds the SNF in each vessel containing the SNF] and absorbed water [water that adheres to the SNF after removal of bulk water]) will be removed from the vessel containing the SNF. After the SNF is dried at the CVDF, it will be moved to the CSB for staging. Once the SNF reaches the CSB, SNF that requires additional drying will be sent to the HCSA for conditioning. -.Process descrigtio_s and other related topics associated with the CVDF and the CSB will be presented in this application for information purposes. The CSB construction began in April 1996.

taging area of the CSB to the HCSA and toxic air and criteria pollutants air emissions n a separate NOC (Phase 11) which will be ent of Ecology (F%ology) in accordance with

Washington Administrative Code (WAC) 173-400 and 460. Construction of the HCSA is scheduled to begin in October 1996. After the SNF is conditioned at the HCSA, the fuel will be returned to the CSB and placed into interim storage for up to 40 years. During the interim storage period, the SNF will be stored in sealed vessels and no emissions will be generated.

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Ms. E. D. Sellers, Director lear Fuels Project Division

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Figure 3. Canister Storase Building and Hot Conditioning System Annex Layout.

DOEIRL-96-49 Revision A

1.2.1 Facility Description

The CSB will be a compfeted version of the 55.78 m by 4,267 rn (183 ft by 140 ft) Hanford Waste Vitrification Plant (HWVP) CSB that was started in January 1993, for storing vitrified glass logs containing radioactive waste. The HCSA will be located on the south end of the CSB (see Figure 3). The RCSA wilf be approximately 9.14 m (30 ft) long by 41.45 m (136 ft) wide by 16.76 m (55 ft) high. Figures 4 and 5 show the basic features of the HCSA. The HCSA will be an extension of the CSB and will house the HCSE.

As originally discussed in the Hot Conditioning Trade Srudy (Fluor Daniel, Inc. 1995) and modified during conceptual design, the HCSA will be the last SNF chemical processing step before final interim storage. The main processes and potential emission p in t s of the HCSA are presented in this NOC. The following description of the HCSA is submitted for approval under this NOC. The information is based on the latest conceptual design at the time of submittal of this - . .

' operational and one

equipment. The process*module will meadre approximately 1.82 m (6 ft) by 2.74 m (9 ft) and is 2.44 m (8 ft) hig& There will be ode process module per process pit. The process modules will be arrangd to allow a 1.22 (4 ft) wide aisle all around to provide access for maintenance. The process module will cantkin the vacuum pump, heat exchanger, valving, instrumentation, and other hot conditioning process equipment that does not, have to be located in the process pit or trench. The trench will be a rectangular cross-section space, 60.96 cm (24 in) wide by 114.30 cm (45 id) deep, located below the HCSA floor level that will connect the with the process module. The piping that connects the vessel

The HCSE will systems. Intake an WI from the HCSA volume, through high-efficiency paniculate air (HEPA contaminated trench,

potentially contaminated pit space, through the potentially HCSE HEPA filter and supply fan, and out the HCSE

stations exhaust syste

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DOFJRL-96-49 Revision A

chilled water system, the gas bottles, and the tube trailers. de'auxiliary facilities will be located to the immediate west of the HCSA.

1.2.2 Location of Facility

The CSB and HCSA will be located at'the site of the unfinished HWVP CSB that was planned for the vitrification program. The HCSA will be located at Hanford Site coordinates N42000, W55800. The HCSA location in the 200 East Area is shown on Figure 2.

1.3 TYPE OF PROPOSED ACTION

This NOC is being submitted for the CVDF in accordance with WAC 173-400-040, "New Source Review" and WAC 173-460-080, 'New Source Review". The HCSA is one of

es that will 6edesignkl and"constructed to complete ih& retrieval, processing, and storage of SNF from the K East and K West Basins. This NOC is being submitted to ensure the HCSA is in full compliance with WAC 173-460-040(8), "Commencement of Construction" This Phase I NOC is defined as constructing the substructure, including but not limited to, pouring the concrete for the floor; construction of the process pits and exterior walls; making necessary interface connections to the CSB ventilation and utility systems for personnel comfort; and extending the multi-canister overpack (MCO) handling machine rails into the HCSA. A Phase I1 NOC will be submitted for approval prior to instillation, and is defined as the completion of the HCSA which consist of installation of HCSE, air emissions control equipment, and emission monitoring equipment. The project is under the management of the U.S. Department of Energy, Richland Operations (DOHRL.) Office and its contractors, working at the Hanford Site SNF Project.

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1.4 STATE ENVIRONLIENTAL POLICY ACT ENVIRONMENTAL CHECKLIST --I

The SNF CVDF is required by WAC 197-11-960 to prepare and submit a '

(Washington) S m e Environmenrai Policy Acf of 1971 (SEPA) checklist to Ecology. In our opinion, the K Basin Environmental Impact Statement @IS) that was prepxed for the SNF


2.0 SOURCE INFORMATION

The following sections provide information regarding the source and the estimated air toxic and criteria pollutants that represent the potential air emissions, resulting from operation of the HCSA. Details on potential emissions generafed by the HCSA process and emission controls will be presented in the Phase I1 NOC.

Section 2.5, HCSA, covers the functional and process operations requiring approval under this NOC. Section 3.0 lists the air toxic and criteria air pollutants of the HCSA requiring approval under this NOC. Information presented in the other sections of this NOC is for background and will be. further developed in the other facilities NOCs.

2.1 PROCESSDESCRIITION , , _. ~ -

Company SNF Project has been assigned the task to remove approximately 2:300 MT (2,530 tons) of SNF from the K East and K West Basins, condition it, and place it into dry storage. The process requires the design and construction of several new facilities, to allow the conditioning and storage of the SNF. The retrieval of the SNF will be accomplished in existing facilities at the K Basins. The objective of the project is to safely remove and condition the SNF for interim storage that can last up to 40 years and may be extended to a total of 75 years. Part of the retrieval process will be to load the SNF into new MCOs for conditioning and interim storage. The new MCOs will be a single use SM: vessel that will be capable of rnaintainidg SNF containment and subcriticality after being closed and sealed. Each MCO will consist of a shell, a shield plug, several rerack baskets, and incidental equipment. Figure 7 illustrates a welded-type MCO assembly. Figure 8 shows a mechanical closure being considered for sealing the MCOs. Either design will Secure the MCO for p

As discussed in the Performance Mulfi-Canisfer Overpack (WHC 1996a), vessel that provides access to its cavity through its top end and receives a shield plug for its closing. The MCOs will be approximately 406.4 cm (160 in.) long with a 60.46 cm (24 in.) diameter. Each MCO will weigh approximately 1,812 kg (4,000 Ibs) empty, and can hold approximately 7,248 kg'(16,000 lbs) of SNF and water (for a full weight of approximately 9,060 kg [20,OCXl lbs] including rerack ba , shell, shield plug, incidental equipment, and

t will be loaded at the basins with SNF elements or SNF fragments. The rerack baskets will be cylindrical annular open-top containers that receive and hold the SNF elements or SNF fragments. Five types of rerack baskets are planned: two types to handle N Reactor SNF, which holds an average of 48 to 54 SNF elements; one t y p e for Single Pass Reactor SNF, which holds 120 single pass SNF elements; and two types for SNF fragments, which holds 50 percent by weight of the rerack

k baskets will be designed to maximize payload and minimize

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Figure 8. Multi-Canister Overpack Mechanical Closure.

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movement during shipping, while considering ease of loading into the MCOs and gas circulation for conditioning.

The shieSd plug provides penetrations, ports and connections, a rupture disk, and an internal and external HEPA filter. The rupture disk and a HEPA filter will be connected to the outside of the shield plug. Incidental equipment includes criticality control structures, a dip tube connecting to ports on the MCO shield plug, features and devices to seal the MCO, and interface features for component handling. TO reach the final interim storage of stabilized SNF in the CSB the following steps will be required:

Retrieval of SNF from the K Basins Cold vacuum drying (CVD) of SNF in the MCOs at the CVDF Staging the MCOs in the CSB Hot conditioning of SNF in the MCOs at the HCSA Interim storage of the MCOs at the CSB.

retrieval, CVD, staging, and interim storage of MCOs are provided only as background information because they are incidental to the HCSA. The descriptions are general in nature because many of the details have not yet been defined and the processes are not part of this NOC. Approval will be obtained, before

CVDF, CSB, and

EL RETRIEVAL FROM THE K BASINS

Basin is stored in closed canisters. The process for retrieval and cleaning of the SM: is discussed in Spent Nuclear Fuels, Fuel Refrieval Sub-project Conceprual Design Repon (LATAIBNFLIFoster Wheeler 1996). The cleaning process will minimize the amount of basin floor sludge and gNF canister sludge that leaves the K Basins. The K Basin project is working on methods to 'treat and dispose of any waste products, such as old SNF canisters, floor, sludge, etc., while minimizing waste and ensuring a safe cleanup which protects the environment. A brief description of the SNF cleaning process which takes place at both K East and K West Basins is presented below. This description supports sound engineering

DOSRL-96-49 Revision A

containing SNF assemblies into the wash basket and closing and locking the containment box lid, The wash basket will be rotated for onecycle, as basin water is flushed through the wash basket and containment box to remove SNF canister sludge and basin floor sludge (accumulated basin dirt and debris) from the SNF.

Upon completion of the initid cycle, rotation of the wash basket will be stopped with the SNF canister in an inverted position. The SNF canister will be removed from the containment box, allowing the SNF assemblies (Figure 9) to discharge to the wash basket. The containment box lid will be closed and locked, and a second cleaning cycle will begin. During the second cleaning cycle, the SNF assemblies will be tumbled as basin water is flushed through the wash basket and containment box to remove SNF canister sludge and basin floor sludge from the individual SNF assemblies.

Some of the SNF assemblies will be moved for disassembling. The SNF assemblies, requiring disassembling will be disassembled by removing the inner SNF element from the outer SNF element. A-prtiunvf the SNF elements will be visually inspected. If a SNF element fails the inspection. it will be subject to a secondary cleaning process. The secondary cleaning station will use a high pressure water jetting system on individual SNF I

elements. The SM: element will be placed into a SNF element cradle within a containment enclosure to remove adhering sludge. The ShT element cradle will align the SNF element axis with the jetting nozzle enabling the high pressure water jetting action to pass through the bore of the element. After cleaning, the SNF elements will be moved to the MCO loading area for placement into the MCO rerack baskets.

loading area the SNF will be placed into the MCO rerack baskets lo the MCOs. Each MCO will be filled and the payload

maximized. Once a MCO is filled with ShF rerack baskets, it will be readied for transportation. At this time the MCO shield plug will be replaced and the MCO sealed by mechanical closure or welding before being removed from the load out pits. Each transport cask will be sealed, and checked for contamination on the external surfaces, after being removed from the basin load out pit. If necessary, the transport cask will be cleaned to

worker protection.

. nliness is governed by safe handling levels and

Each MCO and cask will then be removed from the basin and placed on a SNF transport trailer and readied for transfer by truck to the CVDF. The transport cask wjll provide secondary confinement to the SNF inside the MCO. Once the transport cask is loaded on the SNF transport trailer, it will remain there until it is removed at the CSB.

e Conceptual Design Report for !he Cold Vacuum Drying Syslem will be the first chemical processing step in ensuring proper storage

of the process and the equipment used to remove of the SNF. The following is a descript’

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DOWRL96-49 Revision A

Figure 9. 105-N Reactor Mark IV Spent Nuclear Fuel Element Assembly.

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DOElRG96.49 Revision A

The CVD process will be used to remove as much free water as possible from the MCOs before they are transported to the CSB. Bulk water will be removed by pumping. Remaining absorbed water will be removed by heating to 50°C (122°F) in a vacuum for a period of approximately 24 hours.

The CVD process will arrest further SNF corrosion, reduce the potential for temperature driven excursions, and prevent excessive hydrogen build-up. Cold vacuum drying will not be expected to remove chemically-bound water (water chemically adhered to the SNF). It is estimated that approximately 2 kg (4.41 lbs) of chemically-bound water may not be removed by CVD; thereby, remaining in each MCO.

Following CVD, each MCO will be heated to 75°C (167°F) and held for six hours to verify that the MCO will not overpressurize during transportation to the CSB. Following the post CVDF monitoring, the temperature of each MCO will be lowered to 25°C (77°F) and the MCO inerted with helium at approximately 155.10 mmHG (3 lbf/in*[g]) pressure. The MCOs will then be reIiSsTd’froiT th3 CVDF and transportedan the SNF transport trailer by truck to the CSB.

2.4 MULTI-CAMST

Once the CVDF processing is complete, the MCOs will be transported to the CSB for staging. During transportation to the CSB, the temperature of the MCOs may rise slightly and some hydrogen may be generated from’the reaction of residual water with the SNF. The hydrogen generation reaction rate doubles for each 8.33 to 11.11 “C (15 to 2O’Fj temperature rise. The MCOs are expected to amve at the CSB at a total internal pressure of‘ approximately 1,034 to 1,551 mmHg (20 to 30 lbf/in2[g]).

Each MCO will be unloaded at the CSB from its SNF transport trailer using a crane to move the cask and MCO into the MCO receiving station. The MCO and cask will then be monitored and, if required, connected to a purge system at the receiving statqn.

s buildup due to oxidation.

ipe, the purgdsystem consists of an inert gas cylinder and a vacuum pump, which exhausts to the CSB exhaust stack. By opening and closing a series of valves, the purge system can draw a vacuum on the MCO to remove gases and then change its operation to flow inert gas into the MCO to purge the MCO. When the purge system is coupled to each MCO quick-connect fitting, gas contained in each MCO will flow through a canister-type HEPA filter and the attached flexible connection to a pressure gage. After the pressure is recorded, a sample of the gas will be taken and the temperature of the gas will be recorded. After the sample is secured, the remaining gas in each MCO will be vented through a vent line equipped with testable HEPA filters, leading to the CSB exhaust stack.

Once each MCO is depressurized, a vacuum pump will be used to remove as much of the remaining gas as possible. Purging will then reduce any pressure buildup in each MCO, ensuring an inert internal environment, and will allow staging to begin with the lowest

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possible concentration of hydrogen. It is expected that the MCO internal pressure will depend on the initial pressure, the time elapsed since each MCO was closed, and the internal temperature during that period. The purge system vacuum pump will exhaust into the CSB exhaust, which is connected to the CSB exhaust stack. To complete the purge, each MCO will be refilled with inert gas to reach a slight positive pressure. With purging complete, :he quick-connect canister-type HEPA filter will be removed, the cover on the quick-disconnect will be replaced, and the covers on each MCO HEPA filter and rupture disc will be removed to activate them.

Following purging, each MCO will be transferred and loaded into storage tubes within the CSB by means of the MCO handling machine. The MCO handling machine will have a self-contained dual HEPA filtered ventilation system as shown in Figure 10. The MCO handling machine ventilation system will exhaust filtered air into the operating space of the CSB.

In the CSB the-MCOs will be store$ vertically in storage tubes with one or two MCOs in each storage tube. The storage tubes will be closed with a shield plug that incorporates a redundant seal, a HEPA filtered vent, and a quick disconnect fitting for depressurizing or purging the storage tube. The storage tube HEPA filter on the vent is not testable in service; however, it is pre-tested and has the same effectiveness as the main ventilation filters. A11 MCOs will be vented while being staged at the CSB before hot

sk is unloaded, a new, empty MCO will be loaded into the cask and sent to the K Basins. This cycle is expected to be repeated over a two year period to remove and stage all of the SNF from the basins. Thb MCOs wilI be staged until they are hot vacuum conditioned and placed into interim storage.

2.5 HOT CONDITIONJh'G SYSTEM ANNEX - - I

The following information was first presented in the HOC Condirioning Trade Study (Fluor Daniel, Inc. 1995). Since then Westinghouse Hanford Company has contracted with a design firm to complete the final design of the HCSA and a different design firm for the HCSE to be used to perform the final chemical processing step prior to interim storage of the

ion of the NOC is submitted for approval.

2.5.1 Process Description and Equipment

S N F contained in the MCO will be performed in the HCSA subsequent to the initial CVD done at the CVDF. It will ensure that gas generation from the radiolyses of water and other potentially volatized material does not exceed the sealed MCO design pressure limit. Hot conditioning will consist of heating the SNF to approximately 300 to 350°C (572 to 662°F) under a vacuum. This will remove the chemically bound water and cause a significant portion of the uranium hydride that may be present to decompose and

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release hydrogen from the SNF. A passivation step will be completed to reduce the overall reactivity of the SNF. In the passivation step, the MCO would be cooled to 150°C (302'F) and a controlled moun t of oxygen in an inert gas diluent will be added to the MCO to oxidize highly reactive surfaces.

The process equipment required for hot conditioning will consist of seven hot conditioning process stations, six operational and one auxiliary pit which could be used as a welding area for final sealing of the MCOs, or for neutron interrogation of the MCO to determine residual water content.

Each hot conditioning process station will be comprised of a process pit and a process module, Each process pit will be a hole in the HCSA floor approximately 1.22 m (4 A) in diameter and 6.10 m (20 ft) deep. The process pit will hold the oven where the MCO will be heated and the SNF conditioned. The oven will essentially be a thermos bottle placed within the process pit. The MCO. will be placed inside the oven. Heating will be

r through the oven (Figure 11). A cover ring will be placed between the MCO and oven interior wall

The process module will ntains the hot conditioning process

maintenance. The process module will contain the vacuum pumping system and inert gas purge system to handle gas within the MCO, gas recirculation blower with a heater/cooler,

d other hot conditioning process equipment that does no& have to or trench. The trench will be a rectangular cross section space,

approximately 60.96 cm (24 in) wide by 114.30 cm (45 in) deep, Iocated below the HCSA floor level that will connect the process pit with the process module. The process piping that connects the MCO and oven with the proces odule will be located in the trench.

the working space environment of the HCSA, a portable to make connektions to the MCO while it is in the oven. The be placed over the oven after the MCO is placed in the oven.

The portable process enclosure will contain shielding, a hoist, and tele-operated manipulators, used to make and break connections to the MCO. In addition, the portable enclosure will be used tokplace the cold trap contained in the process piping located in the trench. If required, welding may be accomplished with the portable enclosure at the process pit the MCO is currently in or at the auxiliary pit. The portable enclosure will be fitted with a HEPA filter which wil1,allow HCSA air volume to flow through the oven and trench

ist of a HEPA filter intake, ducted manifold for up to six process stations, isolation nuclear grade dampers, two stage testable HEPA filter plumen with prefilter, variable speed exhaust fan, static pressure sensors, and exhaust stack.

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2.5.2 Process Steps

A MCO wiU. be retrieved from a storage tube in the CSB by the MCO handling machine. The HCSE ventilation system is turned on and allowed to flow from the HCSA, through the process station and trench. The MCO will then be placed into a process pit oven in the HCSA (see Figure 11). The portable enclosure will be placed over an oven and the MCO connections made to the process module and KCSE exhaust and the oven cover closed. After all connections are made the oven cover will be closed and the portable enclosure is removed.

The vacuum system of the hot conditioning process module will be started to initiate flow through the MCO. Inert gas will be heated and bled into the MCO as the vacuum pump maintains the purge flow. The process gases will be circulated through the cold trap and maintained at a temperature that ensures proper heat transfer to the SNF for conditioning. Heating wl?1'6ers6i$&l in thiyrocess station and tlie core temperature of the MCO will be raised to approximately 303 to 350°C (572 to 662°F). The internal pressure of the MCO will be reduced to approximately 6.5E+02 Pa (5 TORR), the MCO will be maintained at this temperature and pressure for approximately 48 hours. During this time the process gas and water and hydrogen will be bled off and sent to the HCSE ventilation system. The process gases will pass through the cold trap where cesium gases, and iodine gases will be collected, and the remaining air pollutants pass through the process lines to the HEPA filters where particulate matter will be collected.

Heating will be stopped at approximately 48 hours and cooling will begin by reducing the temperature of the air flowing through the oven annular space. The MCO temperature will be lowered to approximately 150°C (302°F). A controlled partial pressure of oxygen will be introduced into the MCO, along with an inert carrier gas, to passivate remaining reactive surfaces. The MCO will remain at approximately 150'C (302°F) with oxygen

e. The MCO will be flushed le enclosure will be moved back

over the oven and the oven will be opened. The MCO will be isolated from the process and offgas systems and then disc

The MCO valves 4iI1

.

process station it is contained in or moved to the auxiliary pit. The welding fumes will be collected by the hot conditioning module ventilation exhaust system and dischaiged to the HCS exhaust system and then to the HCS stack. Welding will take place once the MCO has been verified that the SNF has been

storage. The top of the MCO will be surveyed and ensure safe handling. The cold trap will be replaced mount of pollutants collected per MCO. This determination

will be based on radiahon readings, to ensure that the cold trap can be safely handled and disposed of.

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After all disconnections and welding, as applicable, is completed, the portable enclosure wili be moved away from the oven and the MCO handling machine will be brought back to lift the MCO out of the oven and place it back into a CSB storage tube. As a result of hot conditioning, the SNF will be expected to be stabilized for interim storage and the MCO vents wilI be sealed. Some of the MCOs may not be sealed immediately following hot conditioning, some may be placed back into the CSB for continuad staging until it is confirmed that the SNF has been properly conditioned for interim storage. After a MCO is placed into interim storage there is expected to be little or no further potential for emissions from the MCO and storage tubes. Periodic gas sampling and pressure checks of the storage tubes and MCO may be conducted during storage. However, the specific requirements and procedures for testing during storage have not been determined at this time.

2.5.3 Solid WastelProcess Exhaust Gases _. i ,- - The sources of solid waste generated by the HCSE will fall into two categories. The

first is waste as a direct result of operating and conditioning equipment (Le.. HEPA filters, cold traps, and filters used by the monitoring equipment). The second is general cleaning and inspection (Le., welding rods, wipes, swipe test, etc.). The solid waste will be collected in drums and transported by hand carts to the HCSA solid waste staging area. From there the waste will be sent to the appropriate waste disposal or treatment facility.

2.6 INTERIM STORAGE

Upon completion of hot conditioning or upon confirmation the MCO is ready, each MCO will be sealed and'placed in interim storage. The SNF in each MCO is expected to generate minimal gas and oxide particulates during interim storage. Interim storage will end when the sealed MCOs are either shipped to a repository for permanent disposal, or shipped to a yet undefined processing plant. 3ecause the exact outcome of the SNF is not yet defined, the MCOs may remain in interim storage for up to 40 years. In addition to the expected 40-year interim storage period, provisions will be made for extending storage to 75 years, if necessary. Sealed MCOs are not expected to be vented before removal and shipping; thus, no environmental releases are expected during interim storage.

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3.0 EMISSION SOURCE

There are no expected emissions from the construction of the substructure, including but not limited to, pouring the concrete for the floor; construction of the process pits and exterior walls; making necessary interface connections to the CSB ventilation and utility system for personnel comfort; and extending the MCO handling machine rails into the HCSA. The emissions generated at the HCSA will be caused by the process equipment and actual processing of the SNF in each MCO. The installation of the process equipment and associated air pollution control and ventilation system will not occur until a Phase II NOC is approved. An evduation of the material that could be contained in each MCO has been established based on sound engineering judgement and is presented in the following sections.

3.1 CRITERIA POLLUTANTS - a pollutants inventory is listed in Table 1. This table contains the

source of the pollutant from HCS operations based on process knowledge and conceptual design. The majority of the pollutants listed will be generated from the SNF contained in the MCO or the welding of the MCO closed for interim storage. This will mostly consist of metals, however, non-significant volatile organic compounds may also be present. Based on the process description in Section 2.0, there is a very small chance that chemically bound waste contained in the SNF and contained from the MCOs will contain the listed materials. Any additional process, such as back up power generators, will be discussed in separate NOCs as final safety analyses are compl final decisions are made on the necessary

Hot Conditioning System Annex.

PMlO = particulate mattkr

3.2 TOXICAIRPO

is listed in Table 2. This table contains the source of the pollutant from HCS operations based on process knowledge and conceptual design. The majority of'the pollutants listed will be generated from the SNF contained in the MCO or the welding of e MCO closed for interim storage. This will mostly consist of

25


Table 2. Air Toxic Pollutants from the Hot Conditioning System Annex.

. -

the process description in Section 2.0, there is a very small chance that chemically bound water contained in the SNF and conditioned from the MCOs will contain the listed material. Any additional process, such as back up power generators, will be discussed in separate NOCs as final safety analysis are compteted and final decisions are made on the necessary support facilities for the

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D O m 9 6 - 4 9 Revision A

4.0 REFERENCES

DOE, 1994, imegrated Process Stnuem for K Barim Spew Nuclear Fuel, WHC-SD-SNF-SP-005, Volume 1, Rev. 0, July 1995.

Ecology, EPA, and DOE 1994, Hanford Federal Facihy Agreemem ond Consent Order, pi-Party Agreement), as amended, State of Washington Department of Ecology, U.S. Environmental Protection Agency, and U.S. Department of Energy. Olympia, Washington.

Fluor Daniel, Inc., 1995, Hor Conditioning Trade Study, Fluor Daniel Inc. for Westinghouse Hanford Company, Richland, Washington.

LATAIBNFLIFoster Wheeler, 1996, Spenr Nuclear Fuels. Fuel Retrieval Sub-project Conceptual Design Repon, Volume I and 11, LIB-SD-SNF-Rpt-09, Revision 0, LATA/BNFUFosler Wheeler for Westinghouse Hanford Company, Richland Washington.

Washington Administrative Code (WAC) 197-1 1, 1984, State Environmenfal Policy Act Rules, as amended, State of Washington Department of Ecology, Olympia, Washington.

i

Washington Administrat& Code (WAC) 1 Pollution Sources, as amended, Stat Olympia, Washington.

400, 1991, General Regulatiom for Air f Washington Department of Ecology,

Washington Administrative Code (WAC) 1 460, 1991, Controls for New Sources of Toxic Air PoNurams, as amended, State of Washington Department of Ecology, Olympia,

WHC, 1996a, PerSonnu SpecBcation for ;he Spent Nuclear Fuel Muhi-Canister 26, Revision 1, Westinghouse Hanford Company, Richland,

I

WHC, 1996b, Conceptual Design Repon for rhe CoId Vacuum Dving System, WHC-SD-SNF-CDR-003, Revision 0, Memck & Company for Westinghouse Hanford Company, Richland, Washington.

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Elumber ofCo&

OFFSITE 1

1

1

....-

State of Washineton Deuartment of Ekolpgy Mr. Joseph S. Stohr, Section Manager Headquarters, Lacey Section NucIear Waste Program State of Washington Department of Ecology P.O. Box 47600 'Olympia, Washington 98504-7600 Stateof-Washineton DeDartrnent of Heallh Mr. A. W. Conklin, Head Air Emissions and Defense Waste Section Division of Radiation Protection State of Washington Department of Health Airdustrial Park Building 5 , LE-I3 Olympia, Washington 98504-0095 U.S. Environmental Protection AeenCy Ms. A. Frankel, Acting Director Air and Toxics Division U.S. Environmental Protection Agency Region 10

1200 Sixth Avenue Seattle, Washington 98101

Mail Stop AT-082

U.S. Deuartment of Enerev Richland Operations Officp

E.D. Sellers

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DQURL-96-49 Revision A

DISTRIBUTION Westinehouse Ha Central Files ~ 3 - a 8 DOE Reading Room H2-53 S. K. Baker H5-49 F. W. Bradshaw R3-85 R. G. Cowan R3-86 C. DeFigh-Price x3-79 W. T. Dixon H6-2 1 J. E. Filip R3-85 J. R. Frederickson ~ 3 - a 6 W. D. Gallo R3-85 R. G. Gant - X3-I9 L. H. Goldman R3-86 E. W. Gerber R3-86 R. F. Hint H6-25 J. J. Irwin HO-34 E. M. Greager H6-20 M. K. Mahaffey R3-85 L. R. Miska R3-86 J. P. Schmidt X3-78 C. A Thompson R3-85 J. E. Turnbaugh H6-21

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